Heat exchanger for motor vehicles

ABSTRACT

Disclosed is a heat exchanger for motor vehicles, comprising two spaced-apart manifold devices ( 10, 12 ) and several connecting tubes ( 14   a   , 14   b   , 16   a   , 16   b ). Said connecting tubes ( 14   a   , 14   b   , 16   a   , 16   b ) are disposed so as to form two rows of tubes ( 30   a   , 30   b ) which are located next to each other, are penetrated in parallel by the first medium, and are respectively formed by several connecting tubes ( 14   a   , 14   b   , 16   a   , 16   b ) that succeed each other in the longitudinal direction ( 10   a   , 10   b ) of the manifold devices ( 10, 12 ). The direction of flow of the first medium is deflected at least once between the two manifold devices ( 10, 12 ) in each of the rows of tubes ( 30   a   , 30   b ) while the number of changes in the direction of flow between the manifold devices ( 10, 12 ) is identical in the rows of tubes ( 30   a   , 30   b ).

The invention relates to a heat exchanger for motor vehicles, and in particular to a cooler for cooling coolant for a heating or air conditioning system of motor vehicles, and to a device for heating and/or air conditioning the passenger cell of a motor vehicle having such a heat exchanger and a motor vehicle having such a heat exchanger.

Air conditioning systems of motor vehicles generally have a coolant circuit. Carbon dioxide (CO₂) has been increasingly used as the coolant in recent times. The cooling capacity of a CO₂ circuit is decisively determined by the gas cooler. In the embodiment of such gas coolers the tension is generally paid to ensuring that they are pressure-stable even at high temperatures, have a low internal volume and utilize the overall space while allowing for a low weight. In order to minimize power-reducing thermal return flows, one criterion when designing or arranging such gas coolers in motor vehicles may be appropriate connection into areas through which coolant flows.

German Patent Application 102 29 973.0 by the applicant discloses a gas cooler in which a cross flow connection is provided. In this embodiment, two header tubes are provided which are arranged parallel and adjacent to one another. The two header tubes are connected by means of a multiplicity of flat tubes which are bent in a U-shape and each open with their free ends into one of the header tubes. These flat tubes follow one another in the longitudinal direction of the header tubes, in each case an intermediate space through which air can flow being formed between two adjacent flat tubes so that heat can be transmitted between the coolant which is conducted in the flat tubes and the flowing air. The two header tubes which are arranged on the same side of the bundle of flat tubes are each divided in such a way that in each case two chambers are formed in these two header tubes. A lower chamber of one header tube is fluidically connected via a junction piece to another chamber of the other header tube. This junction piece can be mounted at any desired height of the gas cooler and permits transfer of the through-flowing coolant from the region facing away from the air into the region facing the air, or else in the opposite direction. One objective of this embodiment is to prevent the already cooled coolant from being reheated by warm engine reverse flows by adept routing of the coolant.

German Patent Application 102 52 263.4 by the applicant discloses an embodiment of the gas cooler with four header tubes, two of which are arranged in each case in adjacent pairs in order to form a header tube device. The two header tube devices which are formed in this way are spaced apart from one another and are fluidically connected via a multiplicity of connecting tubes or gas cooler tubes. These gas cooler tubes run on two planes which are spaced apart from one another, or form two rows of tubes. They are each of essentially straight embodiment and open with their distal ends in each case into one of two header tube devices, or into separate header tubes. Therefore, in this embodiment, instead of the tube forks which are known from DE 102 29 973.0 or flat tubes which are bent in a U shape, in each case two tubes of identical length are used. In each case two chambers which are spaced apart axially are formed in the header tubes. On a gas cooler side, a lower chamber of one of the header tubes is fluidically connected to an upper chamber of the other header tube via a junction piece. The connecting tubes are connected in such a way that the coolant firstly flows through the entire end face plane and then through the junction piece and into the end face plane which is located in front of it or behind it.

In the abovementioned embodiments, a junction piece which connects surface squares to one another is necessary. Such a junction piece is cost-intensive both to manufacture and mount and can give rise to leaks, specifically in particular if different temperatures of the squares additionally stress the solder seams. In addition, the transfer can form a bottleneck, which can have a disadvantageous effect on the drop in pressure on the coolant side, resulting in a lower coolant capacity. Furthermore, in the transfer region one to two rows of tubes are not available for the cooling capacity. A parallel flow solution is not possible with this embodiment.

EP 0 414 433 B1 discloses a heat exchanger in which two rows of flat tubes which are arranged in parallel and which each fluidically connect two header tubes which are spaced apart are formed. In each case ribs through which air can flow through the heat exchanger transversely with respect to the longitudinal extent of the flat tubes are provided in the respective rows between flat tubes which are adjacent in the longitudinal direction of the header tubes. The inflow is connected to the two rows of flat tubes on the same side of the heat exchanger. In the row of tubes which faces the fresh air, the flow direction changes once, and the flow direction changes three times in the row of tubes facing away from the fresh air.

The invention is based on the object of providing a heat exchanger for motor vehicles, in particular a cooler for cooling coolant for a heating or air conditioning system of a motor vehicle which exhibits good transfer characteristics and can be manufactured cost-effectively and easily in terms of fabrication technology.

According to the invention, a heat exchanger according to claim 1 or according to claim 2 or according to claim 4 is proposed. A device according to the invention for heating and/or air conditioning the passenger cell of a motor vehicle is the subject matter of claim 13. A motor vehicle according to the invention is the subject matter of claim 14. Preferred embodiments are the subject matter of the subclaims.

Each header tube device preferably has at least two header tubes. Particularly preferably, each header tube device has separate header tubes for each row of connecting tubes and for each component heat exchanger, respectively. Here, there is in particular provision for the longitudinal axes of these header tubes of the respective same header tube device to be spaced apart and to run, for example, parallel to one another. A header tube can also be formed from a plurality of separate, and in particular concentric, header tube sections which are spaced apart in the axial direction, specifically forming an intermediate space or without forming such intermediate spaces.

In an embodiment which is to be particularly preferred, two rows of header tubes or two component heat exchangers are provided, the two rows of header tubes each having two header tubes which are arranged in parallel and offset to one another. In this context, connecting tubes of one of the rows of connecting tubes or of one of the component heat exchangers open into the respective one header tube, and connecting tubes of the other row of tubes or of the other component heat exchanger open into the respective other header tube. Therefore, in particular four header tubes are provided in this context.

The component heat exchangers are preferably each of essentially identical embodiment. It is possible to provide for them to differ in the position of their inlet opening and/or outlet opening and to be otherwise of identical embodiment. However, there is preferably provision here that various positions of the inlet and/or outlet openings are such that they nevertheless open, with respect to the various component heat exchangers, into corresponding regions or chambers.

The connecting tubes are preferably each flat tubes. Here, in a particularly preferred embodiment there is provision for their respective—two—end regions to be rotated or twisted with respect to the region lying between them. The angle of rotation is preferably between 10° and 110° in each case, particularly preferably between 80° and 100°. It is, for example, essentially 90°.

In a particularly preferred embodiment the flat tubes open with their rotated or twisted end regions in each case into header tubes in such a way that their cross sections extend essentially in the direction of the longitudinal axes of the header tubes, viewed perpendicularly to the longitudinal axis of the flat tubes. Particularly preferably, they extend, apart from the rotated or twisted junction regions, between the end regions with their longer sides of the cross-sectional faces perpendicular to the longitudinal axes of the header tubes.

The connecting tubes, in particular flat tubes, can be embodied in such a way that they form precisely one duct in their interior or in such a way that a plurality of ducts, in particular respectively parallel ducts, are formed in their interior in each case. All the connecting tubes are preferably embodied in a continuously straight fashion. Particularly preferably, all the connecting tubes lie parallel to one another. In one advantageous embodiment, all the connecting tubes are of equal length. It is also preferred for all the header tubes to be of equal length. The header tubes preferably each have a circular internal cross section. The header tubes can, for example, each be made essentially rotationally symmetrical with respect to their particular longitudinal axis.

The connecting tubes of a respective row of connecting tubes or of a respective component heat exchanger are preferably arranged in a respective plane. In an embodiment which is to be particularly preferred, the planes which are thus determined for various rows of connecting tubes or component heat exchangers are located parallel and offset with respect to one another.

In an embodiment which is to be preferred, the various rows of connecting tubes or component heat exchangers are arranged with respect to one another in such a way that air flowing transversely with respect to the connecting tubes successively flows through the intermediate spaces of the various rows of connecting tubes or component heat exchangers which are formed between the connecting tubes. There is provision in particular that air, which in particular forms a second heat transfer medium, successively or sequentially flows through the various rows of connecting tubes or component heat exchangers, specifically outside the connecting tubes. There is thus in particular provision that the second heat exchanging medium, in particular air, is conducted past the first heat exchanging medium, in particular coolant, in a cross flow arrangement in order to bring about a transfer of heat.

In each case a plurality of connecting tubes are preferably connected in parallel in a respective row of connecting tubes or a respective component heat exchanger. This may in particular be such that in a respective row of connecting tubes in each case a plurality of such connecting tubes have a parallel flow through them and subsequently, in particular in the opposite flow direction, other connecting tubes of the same row of connecting tubes or of the same component heat exchanger also have a parallel flow through them. This may be such that depending on the row of connecting tubes or component heat exchangers a plurality of groups of connecting tubes which respectively have a parallel flow through them are connected in series by means of assigned header tubes in such a way that the first medium, in particular coolant, can flow respectively in opposite flow directions through the connecting tubes of successive groups. It is in particular possible to provide that the first medium is made to extend in a serpentine-like fashion in each of the component heat exchangers or rows of connecting tubes.

The number of diversions or of respectively successive opposed flow directions is preferably identical here in the component heat exchangers or rows of connecting tubes. It is possible to provide that the number of connecting tubes which respectively form a group of connecting tubes through which there is a parallel flow in the flow direction increases or decreases downstream in a respective row of connecting tubes or a respective component heat exchanger, or is identical.

Here, two or more of such groups in the respective component heat exchanger or the respective row of connecting tubes are connected in series. Other embodiments are also preferred.

Dividing walls are preferably provided in at least one header tube device. Particularly preferably, in each case at least one dividing wall is provided in various header tubes of the same header tube device. Such dividing walls are in particular such that they separate regions or chambers which follow one another in their longitudinal direction of the respective header tube. It is also possible to provide that in each case at least one dividing wall is provided in the two header tube devices or the corresponding header tubes. It is also possible to provide in each case a plurality of dividing walls which are spaced apart axially in the header tubes of the respective same header tube device, the number of dividing walls in different header tubes of the same header tube device being particularly preferably identical.

A thermal separation is preferably provided between the groups of connecting tubes through which liquid successively flows in opposite directions. For this purpose, it is possible, for example, for the pitch or the distance between adjacent connecting tubes between these groups to be larger than within the respective groups.

The two component heat exchangers, or adjacent component heat exchangers, may be arranged relative to one another in such a way that they are in contact with one another. They can, for example, be soldered to one another. Preferably only one medium, the first medium such as a coolant, flows in the interior of the system formed from the header tubes and the connecting tubes. The second heat exchanger medium, such as air, preferably flows past on the outside of the connecting tubes during operation, specifically in particular transversely with respect to the longitudinal extent of the connecting tubes in this context. The heat exchanger according to the invention is preferably a gas cooler or condenser for a motor vehicle. The heat exchanger is preferably made of aluminum.

In addition, a device according to claim 13 is proposed according to the invention.

In addition, a motor vehicle according to claim 14 is proposed according to the invention. The heat exchanger according to the invention is preferably installed in the motor vehicle in such a way that the planes which respectively extend through the component heat exchangers or the rows of tubes are located transversely, in particular perpendicularly, to the direction of travel. It is also preferred for a fan to be provided for the heat exchanger according to the invention, which fan drives air through the intermediate spaces formed between the connecting tubes. The heat exchanger is preferably arranged with respect to the internal combustion engine of the motor vehicle in such a way that the region of the coolant inlet is heated to a greater extent by a reverse flow of warm air from the internal combustion engine, than the region of the coolant outlet.

Exemplary embodiments of the invention will be explained below with reference to the figures, of which:

FIG. 1 shows an exemplary heat exchanger according to the invention in a schematic illustration;

FIG. 2 is a basic diagram showing the flow routing of the coolant in the embodiment according to FIG. 1;

FIG. 3 a shows a first exemplary embodiment and arrangement of rows of tubes and corrugated ribs;

FIG. 3 b shows a second exemplary embodiment and arrangement of rows of tubes and corrugated ribs; and

FIG. 3 c shows a third exemplary embodiment and arrangement of rows of tubes and corrugated ribs.

FIG. 1 shows an exemplary heat exchanger 1 according to the invention having a first header tube device 10, a second header tube device 12, a multiplicity of connecting tubes 14 a, 14 b, 16 a, 16 b and having an inlet opening 18 and an outlet opening 20 for a first medium such as, in particular, carbon dioxide (CO₂)

The heat exchanger 1 can advantageously be used as a gas cooler or condenser for an air conditioning system or heating system of a motor vehicle. It is possible to provide in this context that a coolant, which is CO₂ in a particularly advantageous embodiment, flows through this gas cooler or condenser.

The header tube devices 10, 12 each have two header tubes 22, 24 and 26, 28. The header tubes 22, 24 of the first header tube device 10 and the header tubes 26, 28 of the second header tube device 12 are each arranged adjacently in pairs, specifically in particular in such a way that their longitudinal axes 22 a, 24 a and 26 a, 28 a extend in parallel and spaced apart from one another. In addition, the longitudinal axes 22 a, 24 a are arranged parallel to the longitudinal axes 26 a, 28 a and the longitudinal axis 10 a of the first header tube device 10 is arranged parallel to the longitudinal axis 12 a of the second header tube device 12.

The heat exchanger 1 has two rows 30 a, 30 b of tubes. These rows 30 a, 30 b of tubes are each formed by a multiplicity of connecting tubes 14 a, 16 a and 14 b, 16 b which follow one another, viewed in the longitudinal direction 10 a, 10 b of the header tube devices 10, 12, with the longitudinal axes of these connecting tubes 14 a, 16 a and 14 b, 16 b being oriented parallel to one another.

The row 30 a of tubes is arranged adjacent to the row 30 b of tubes, the connecting tubes 14 a, 16 a, or all the connecting tubes 14 a, 16 a of the first row 30 a of tubes respectively connecting the first header tube 22 of the first header tube device 10 to the first header tube 26 of the second header tube device 12, and the connecting tubes 14 b, 16 b, or all the connecting tubes 14 b, 16 b, of the second row 30 b of tubes respectively connecting the second header tube 24 of the first header tube device 10 to the second header tube 28 of the second header tube device 12. The connecting tubes which are associated with a row 30 a or 30 b of tubes lie in one plane. The longitudinal axes of the connecting tubes 14 a, 14 b, 16 a, 16 b, or of all the connecting tubes 14 a, 14 b, 16 a, 16 b, respectively extend perpendicularly to the longitudinal axes 10 a, 12 a of the header tube devices 10, 12.

The connecting tubes 14 a, 14 b, 16 a, 16 b and the rows 30 a, 30 b of tubes are, in the embodiment according to FIG. 1, arranged essentially in the manner explained or shown with reference to FIG. 3 a. Here, in particular ribs or corrugated ribs 70 are provided. However, it is also possible to provide a different embodiment to this, specifically such as is explained or shown with respect to FIG. 3 b or with respect to FIG. 3 c. It is thus possible to provide in particular for the rows 30 a, 30 b of tubes to be arranged offset with respect to one another by the amount t/2 (half pitch), specifically viewed in particular in the longitudinal direction of the header tube devices 10, 12. It is possible to provide here that, instead of respectively continuous common corrugated ribs 70, (cf. FIG. 3 a), in each case two separate corrugated ribs 70 a, 70 b are provided (cf. FIG. 3 b). However, it is also possible to provide that in each case a common, offset corrugated rib 70 is provided (cf. FIG. 3 c).

The connecting tubes 14 a, 14 b, 16 a, 16 b are of straight embodiment between their opposite ends and embodied as flat tubes. The planes which extend through the main direction of extent of the respective flat tubes respectively extend perpendicularly to the longitudinal axes 10 a, 12 a of the header tube devices 10, 12.

However, in a preferred embodiment, the respective opposite end regions of the flat tubes are rotated about the longitudinal axis of the respective flat tube specifically preferably through 90°, but it is also possible to provide different angles of rotation. In embodiments in which the angle of rotation is 90°, there is preferably provision for the main direction of extent of these ends to be located in the direction of the longitudinal axes 10 a, 12 a, viewed in the cross section perpendicular to the longitudinal axis of the respective flat tube. Between these ends, the corresponding main direction of extent of the flat tubes, or of all the flat tubes, is, as already mentioned, essentially perpendicular to the longitudinal axes 10 a, 12 a of the header tube devices 10, 12. This has the advantage that smaller (internal) cross sections of the header tubes 10, 12 can be implemented. Thus, for example in the embodiment according to FIGS. 14 and 15 in EP 0 814 433 B1, the internal diameter of the header tubes is bounded in the downward direction by the width of the flat tubes, which does not have to be compulsory according to the invention. However, according to the invention the respective internal diameter of the header tubes can also be larger than the width of the flat tubes.

The header tubes 22, 24, 26, 28, or all the header tubes 22, 24, 26, 28, have, in an advantageous embodiment, a circular internal cross section, specifically in particular in a continuous fashion. Particularly preferably, their outer casing can also be circular or cylindrical in embodiment.

With their respective opposite ends (of the connecting tubes) which can particularly advantageously be embodied in such a way that the openings which are respectively provided there are arranged at the end sides, these connecting tubes 14 a, 16 a, 14 b, 16 b are respectively inserted into the header tube devices 10, 12 so that the two header tube devices 10, 12 are fluidically connected via each of the connecting tubes 14 a, 16 a, 14 b, 16 b. The connecting tubes 14 a, 16 a open, at one end, into the first header tube 22 of the first header tube device 10, and at the other end into the first header tube 26 of the second header tube device 12, and the connecting tubes 14 b, 16 b open, at one end, into the second header tube 24 of the first header tube device 10, and, at the other end, into the second header tube 28 of the second header tube device 12. For this purpose, corresponding openings are formed in the outer faces of the header tubes and said openings are respectively slit-shaped in an advantageous embodiment, and particularly preferably extend in the longitudinal direction of the respective header tube. It is also possible to provide for such slits to be dimensioned in such a way that they can accommodate the ends of a plurality of connecting tubes. However, it is also preferred for each slit to accommodate precisely one connecting tube. The connecting tubes 14 a, 16 a, 14 b, 16 b are connected, in particular soldered, preferably hard soldered, in these regions in each case to the respective header tubes 22, 24, 26, 28 or header tube devices.

The respectively two junction regions between the two rotated or twisted end regions 32 and 34, on the one hand, and the region located between these ends, on the other, can, for example, serve as stops; in other words the connecting tubes 14 a, 16 a, 14 b, 16 b are respectively pushed by their ends 32, 34 into a header tube to such an extent that the region located between these ends, which is rotated with respect to the ends, or vice versa, strikes against the relevant header tube. These junction regions can thus form a mounting aid. However, the ends can also be pushed in in such a way that there is no stop effect in the sense specified above.

In each case intermediate spaces 36 a, 38 a, 40 a for the flow of air are formed between respectively adjacent connecting tubes 14 a, 16 a of the first row 30 a of tubes. In a corresponding way, in each case intermediate spaces 36 b, 38 b, 40 b for the flow of air are formed between respectively adjacent connecting tubes 14 b, 16 b of the second row 30 b of tubes. Air can thus flow through the heat exchanger 1 transversely with respect to the longitudinal direction of the connecting tubes 14 a, 16 a, 14 b, 16 b so that during operation heat can be transferred between the medium flowing through the connecting tubes 14 a, 16 a, 14 b, 16 b and the air flowing through the intermediate spaces 36 a, 38 a, 40 a, 36 b, 38 b, 40 b. The flowing air and its flow direction are indicated schematically in FIG. 1 by the arrow ends or arrows 42. Ribs are advantageously arranged in the intermediate spaces 36 a, 38 a, 40 a. Air can also flow through the latter in the direction of air flow.

The first header tube 22 of the first header tube device 10, the first header tube 26 of the second header tube device 12, and the connecting tubes 14 a, 16 a which open with their ends into these header tubes 22, 26 form a first component heat exchanger or first component cooler 44 a of the heat exchanger 1; in a corresponding way the second header tube 24 of the first header tube device 10, the second header tube 28 of the second header tube device 12 and the connecting tubes 14 b, 16 b which open with their ends into these header tubes 24, 28 form a second component heat exchanger or second component cooler 44 a of the heat exchanger 1. These component heat exchangers 44 a, 44 b are arranged one behind the other in the airflow direction 42, in which case, in an embodiment which is to be particularly preferred, the intermediate spaces 36 a, 38 a, 40 a of the first component heat exchanger 44 a are aligned with those of the second component heat exchanger.

Viewed in the longitudinal direction of the header tubes 22, 24, 26, 28, the heat exchanger 1 has a terminating plate 46, 48 at the top and at the bottom respectively. These terminating plates 46, 48 can, for example, be such that they essentially cover the arrangement of the connecting tubes, viewed in their longitudinal direction or transversely thereto. They can, in particular, cover both rows of connecting tubes. They may also be such that they additionally cover the header tubes at the top or at the bottom; however, these can also respectively have closures—which are different from the terminating plates 46, 48—at their ends. The terminating plates 46, 48 may be formed, for example, from sheet metal plates.

One or more header tubes 22, 24 are respectively provided with at least one dividing wall 50, 52. By means of such dividing walls 50, 52 it is possible to form various chambers 54, 56 and 58, 60 in the respective header tube 22 or 24. This may in particular be such that the dividing wall 50 or 52 separates chambers 54, 56 or 58, 60 which are arranged adjacently in the axial direction of the respective header tube.

For example, a dividing wall 50, 52 can, as shown in FIG. 1, be provided on the inlet side or coolant inlet side or the header tube or tubes 22, 24 arranged there or in the header tubes in which the inlet openings for the entry of the first medium, such as CO₂, are arranged.

According to FIG. 1, the two header tubes 22, 24 which lie on the coolant inlet side each have a dividing wall 50, 52; it is possible to provide in particular for all the header tubes 22, 24 of the first header tube device to respectively form a dividing wall 50, 52.

The dividing walls 50, 52 which are arranged in various header tubes 22, 24, or in the two header tubes 22, 24, of the same header tube device 10 can be positioned in such a way that they delimit regions which are the same in terms of area or volume. This may in particular be such that the regions which are delimited in one 22 of the header tubes 22, 24 by the dividing wall 50 positioned there are identical in terms of area or volume to the regions delimited in the other 24 of the two header tubes 22, 24 by the dividing wall 52 provided there. In particular there is provision that these two header tubes 22, 24 are of identical length. It is also possible to provide, irrespective of the position of such dividing walls 50, 52, that the header tubes 22, 24 and 26, 28 of the same header tube device 10 or 12 are of identical length: in addition it is possible to provide that all the header tubes 22, 24, 26, 28 are of identical length. In a preferred embodiment, all the connecting tubes 14 a, 14 b, 16 a, 16 b are also of identical length.

It is possible to provide, as shown in FIG. 1, that the header tubes 22, 24, 26, 28, and in particular the respectively adjacent ones 22, 24 and 26, 28, are aligned with one another at their ends.

In the embodiment according to FIG. 1, the (two) header tubes 22, 24 of the first header tube device 10 which are located on the coolant inlet side each have a dividing wall 50, 52 which separates the region of the “warm” zone and the “relatively cold” zone. The two dividing walls delimit regions which are equal in area or volume there. It is also possible to provide that the dividing walls 50, 52 delimit different regions or slightly different regions. Thus, it is possible, for example, to provide for the region facing the fresh air to differ in its embodiment by one to three flat tubes or connecting tubes. However, there is particularly advantageously provision for the dividing walls 50, 52 to be positioned in such a way that in each case the same number of connecting tubes opens into the regions of the header tubes 22, 24, thus separated from one another, of the same header tube device 10.

The coolant which enters through the inlet opening 18 advantageously has an inlet temperature there, said temperature being in the range from 150° C. to 180° C. This coolant is cooled along the flow paths by means of the air flowing transversely with respect to the connecting tubes. This may occur, for example, in such a way that the outlet temperature of the coolant is, for example, approximately 50 to 140 Kelvin below the inlet temperature. For example, the inlet temperature can be approximately 180° C. and the outlet temperature approximately 45° C.

The inlet opening 18 of the heat exchanger forms a common inlet opening through which the medium which is subsequently divided—in the flow direction—between the two component heat exchangers 44 a, 44 b enters. In order to enter the two component heat exchangers 44 a, 44 b, an inlet opening (not illustrated in FIG. 1) is provided downstream of the inlet opening 18 in the first header tube 22 of the first header tube device 10, and an inlet opening (likewise not illustrated in FIG. 1) is provided in the second header tube 24 of the first header tube device 10. In a corresponding way, the outlet opening 20 of the heat exchanger 1 forms a common outlet opening, outlet openings (not illustrated in each case) being provided in the first header tube 22 of the first header tube device 10 and in the second header tube 24 of the first header tube device 10, said outlet openings being provided upstream of the outlet opening 20.

In the embodiment according to FIG. 1, the medium is conducted in such a way that it also exits again on the inlet side, which is located here on the side of the first header tube device 10; it is also possible to provide that the inlet side and the outlet side of the heat exchanger 1 are located on different sides, that is to say for example the inlet side is located on the side of the first header tube device 10 and the outlet side on the side of the second header tube device 12, in which case outlet openings are then provided in the first header tube 26 and second header tube 28 of the second header tube device 12, and the common outlet opening 20 is located downstream of these outlet openings, on the side of the second header tube device 12.

In the region of the inlet opening 18 and in the region of the outlet opening 20, a flange or fluid connecting piece 62, 64 is respectively provided for the entering or exiting medium, the inlet opening 18 or the outlet opening 20 being provided in said flange or fluid connecting piece 62, 64.

In the embodiment according to FIG. 1, the header tube device or a header tube device—or respectively its header tubes—acts as a diverter device.

After the coolant from the two rows 30 a, 30 b of tubes has flowed through the heat exchanger 1 in its lateral direction, it is diverted in the two header tubes 26, 28 lying opposite one another before then leaving the heat exchanger 1 again on the inlet side.

It is also possible to provide that the medium or coolant is routed in a serpentine-like fashion by using a plurality of dividing walls. This can lead, for example, to the inlet and outlet of the coolant being positioned diagonally. It is, however, also possible to arrange more dividing walls, which can partially be positioned in the header tubes of the first header tube device and partially in the header tubes of the second header tube device, in such a way that the coolant exits again on the inlet side.

It is also possible to provide that a thermal separation is provided between the warm and cool zones or respectively adjacent connecting tubes, which are flowed through in opposite directions, of the same component heat exchanger or of the respective same row of tubes. This thermal separation can be achieved, for example, by virtue of the fact that the header tubes are given a different pitch at the locations where the dividing wall comes to rest so that the rib is soldered there to just one of the (respectively two) adjacent connecting tubes or flat tubes of one, or of a respective, row of connecting tubes or flat tubes.

The pitch or the distance between adjacent connecting tubes or flat tubes can be the same in each case. It is possible to provide here that, in order to reach thermal separation in the junction region between a relatively cold zone, or the relatively cold zone, and a relatively warm zone, or the relatively warm zone, a relatively large distance is provided between the adjacent connecting tubes, which are flowed through in different directions, of the respective same row 30 a, 30 b of connecting tubes. It is possible to provide that the extent of all the ribs is identical in the direction of the longitudinal axes 10 a, 12 a of the header tube devices. These ribs can, for example, be soldered to the respectively adjacent connecting tubes (viewed in the longitudinal direction 10 a, 12 a). It is also possible to provide that the ribs respectively extend over both component heat exchangers so that in each case one rib, or a common rib, for both component heat exchangers or both rows 30 a, 30 b of tubes is provided between the respectively adjacent connecting tubes.

If a thermal separation is provided, it is possible to provide that, in the region in which a relatively large distance is formed between adjacent connecting tubes for the purpose of thermal separation, the rib or ribs arranged there are respectively soldered to just one of the connecting tubes which is adjacent there in the longitudinal direction 10 a, 12 a.

Ribs can also be respectively provided in the rows 30 a, 30 b of connecting tubes, between the upper terminating plate 46 and the adjacent connecting tube 14 a or 14 b in the longitudinal direction 10 a, 12 a. In addition, ribs can also be respectively provided in the rows 30 a, 30 b of connecting tubes, between the lower terminating plate 48 and the adjacent connecting tube 14 a or 14 b, adjacent in the longitudinal direction 10 a, 12 a, of a respective row of connecting tubes.

In one advantageous embodiment, the heat exchanger 1, which has the two component heat exchangers 44 a, 44 b, is embodied in one piece or connected to form a single-piece component. In one advantageous embodiment it can be embodied as a soldered structure.

Instead of a header tube which is divided into chambers 54, 56, 58, 60 by a dividing wall 50, 52, it is also possible to provide separate, header tube sections which are spaced axially apart or follow one another, the cross sections of such header tube sections being preferably identical and said sections being preferably arranged concentrically.

In the embodiment according to FIG. 1, in each case fewer connecting tubes through which there is a parallel flow (in the same flow direction) are provided on the inflow side than on the outflow side in the respectively identical component heat exchanger 44 a, 44 b.

The component heat exchangers 44 a, 44 b are respectively of identical embodiment in the embodiment according to FIG. 1, specifically in particular with respect to the routing of the flow between the inlet opening and the outlet opening of the respective component heat exchanger 44 a, 44 b. The ribs can be embodied and arranged identically in the two component heat exchangers 44 a, 44 b, in particular if common ribs are not provided. The identical routing of the flow can have fluidic advantages in both applications. It is particularly advantageously possible to provide that both component heat exchangers are of identical embodiment, which is advantageous fluidically, especially since in particular the large number of components of different embodiment can be reduced. However, it is to be noted that the respective inlet and outlet openings of the two component heat exchangers can be positioned differently, specifically in particular in such a way that they open into corresponding chambers at different heights and/or rotated about the longitudinal axis of the header tubes; however, they can also be of the same embodiment.

In the embodiment according to FIG. 1 there is in particular provision that when the first medium enters the first header tube devices 10, said first medium, in particular coolant, is divided into at least two partial flows, preferably precisely two partial flows, between the connecting tubes 14 a, 16 a and 14 b, 16 b, in particular flat tubes, of the first row 30 a of tubes and the second row 30 b of tubes. This may be in particular such that this division is brought about for the entry of the first medium by means of the connecting piece 62. For this purpose it is possible for example, to provide that the connecting piece 62 has at least one inlet opening and at least two outlet openings, a flow connection being produced to the interior of the first header tube 22 of the first header tube device 10 via one of these outlet openings, and a flow connection being produced to the interior of the second header tube 24 of the first header tube device 10 via another of these outlet openings. Corresponding openings, which permit the entry of the medium into the header tubes 22, 24, are provided in the header tubes 22, 24. The volume flow of the first medium may be divided here for example, with a ratio of 50%:50%; however, different ratios are also preferred.

The coolant enters both rows of tubes simultaneously via the flange, preferably taking into account the position of the warmest zone.

The heat exchanger 1 according to FIG. 1 has a low weight, in particular by using two narrow rows of flat tubes and/or by using thin-walled header tubes. The need for a cost-intensive junction piece is eliminated and the soldering reliability is increased. A drop in pressure on the coolant side is reduced. All the flat tubes contribute to the cooling capacity, which brings about an increase in performance.

FIG. 2 is a schematic view of the routing of the flow for the embodiment according to FIG. 1.

From FIG. 2 is it also possible to see that when the first medium enters the first header tube device 10 said first medium is divided into two partial flows between the flat tubes or connecting tubes 14 a, 16 a and 14 b, 16 b of the first row (30 a) of tubes and the second row (30 b) of tubes.

FIGS. 3 a, 3 b and 3 c show, in each case in a partially sectional view, exemplary embodiments of the rows 30 a, 30 b of tubes and their relative arrangements or exemplary embodiments for the configuration of ribs which are arranged between connecting tubes of the rows of tubes. These embodiments which are shown in FIGS. 3 a to 3 c can, in a preferred development, be provided in embodiments according to the invention, specifically in particular in the embodiment according to FIG. 1 or that according to FIG. 2. It is to be noted in this respect that the number of ribs or connecting tubes (per row) is generally larger or significantly larger than is shown schematically or in a detail in FIGS. 3 a to 3 b.

In the embodiments according to FIGS. 3 a to 3 c there is provision for corrugated ribs or ribs 70 to be positioned in intermediate spaces 36 a, 36 b and 38 a, 38 b and 40 a, 40 b, preferably in all the intermediate spaces 36 a, 36 b, 38 a, 38 b, 40 a, 40 b, which are provided between respectively adjacent connecting tubes 14 a-14 a and 14 a-16 a and 16 a-16 a and 14 b-14 b and 14 b-16 b and 16 b-16 b, respectively, of the rows 30 a, 30 b of tubes.

In the embodiments according to FIGS. 3 a to 3 b there is provision in particular that the pitch t of the first row 30 a of tubes corresponds to the pitch t of the second row 30 b of tubes, and particularly preferably is constant in each case. It is also possible to provide that, between successive connecting tubes 14 a-16 a and 14 b-16 b, which are flowed through in opposite directions, in the respective rows 30 a, 30 b of tubes, a different distance between these connecting tubes or a different pitch is provided. This different distance or this different pitch can, for example, be larger, for the purpose of thermal separation, than between the remaining, respectively adjacent connecting tubes of the respective same row 30 a, 30 b of tubes.

In FIGS. 3 a to 3 b the respective arrow 42 indicates the (preferred) inflow direction of the air. It is to be noted that identical reference symbols in the figures designate components which substantially correspond to one another.

FIG. 3 a shows an exemplary embodiment in which the connecting tubes of adjacent rows 30 a, 30 b of tubes are not significantly offset with respect to one another. A connecting tube 14 b or 16 b of the second row 30 b of tubes is arranged adjacent to each connecting tube 14 a or 16 a of the first row 30 a of tubes, viewed perpendicularly with respect to the longitudinal direction of the rows 30 a, 30 b of tubes. In this context it is to be noted, however, that the number of connecting tubes in the two rows of tubes can also differ so that a connecting tube 14 b or 16 b of the second row 30 b of tubes is not arranged next to each connecting tube 14 a or 16 a of the first row 30 a of tubes. In the embodiment according to FIG. 3 a, the connecting tubes 14 a, 14 b and 16 a, 16 b are embodied as flat tubes, with adjacent flat tubes of different rows 30 a, 30 b of tubes extending essentially in identical planes.

In the embodiment according to FIG. 3 a, the ribs 70 are common or continuous ribs 70 for both rows 30 a, 30 b of tubes. There is also provision for the ribs 70 to extend respectively between adjacent connecting tubes 14 a or 16 a of the first row 30 a of tubes and between adjacent connecting tubes 14 b and 16 b of the second row 30 b of tubes, there being in particular provision for these ribs 70 to be respectively formed in one piece.

FIG. 3 b shows an embodiment in which the rows 30 a, 30 b of tubes are arranged offset with respect to one another by a half pitch t/2. In the embodiment according to FIG. 3 b, separate or different corrugated ribs or ribs 70 a, 70 b are provided for the rows 30 a, 30 b of tubes.

In the embodiment shown in FIG. 3 c, the rows 30 a, 30 b of tubes are arranged offset with respect to one another by half a pitch t/2, as in the embodiment according to FIG. 3 b. The embodiment according to FIG. 3 c differs from the embodiment shown in FIG. 3 b essentially in the fact that common, offset corrugated ribs or ribs 70 are provided for the rows 30 a, 30 b of tubes instead of different corrugated ribs or ribs 70 a, 70 b (cf. FIG. 3 b).

LIST OF REFERENCE NUMERALS

-   1 Heat exchanger, gas cooler -   10 First header tube device -   10 a Longitudinal axis of 10 -   12 Second header tube device -   12 a Longitudinal axis of 12 -   14 a Connecting tube or flat tube -   14 b Connecting tube or flat tube -   16 a Connecting tube or flat tube -   16 b Connecting tube or flat tube -   18 Inlet opening -   20 Outlet opening -   22 Header tube -   22 a Longitudinal axis of 22 -   24 Header tube -   24 a Longitudinal axis of 24 -   26 Header tube -   26 a Longitudinal axis of 26 -   28 Header tube -   28 a Longitudinal axis of 28 -   30 a First row of tubes -   30 b Second row of tubes -   32 First end region of 14 a, 14 b, 16 a, 16 b -   34 Second end region of 14 a, 14 b, 16 a, 16 b -   36 a Intermediate spaces between 14 a and 14 a -   36 b Intermediate spaces between 14 b and 16 b -   38 a Intermediate spaces between 14 a and 16 a -   38 b Intermediate spaces between 14 b and 16 b -   40 a Intermediate spaces between 16 a and 16 a -   40 b Intermediate spaces between 14 b and 16 b -   42 Arrow, airflow -   44 a First component heat exchanger of 1 -   44 b Second component heat exchanger of 1 -   46 Terminating plate -   48 Terminating plate -   50 Dividing wall in 22 -   52 Dividing wall in 24 -   54 First chamber in 22 -   56 Second chamber in 22 -   58 First chamber in 24 -   60 Second chamber in 24 -   62 Flange or connecting piece for medium to enter -   64 Flange or connecting piece for medium to exit -   70 Corrugated rib -   70 a Corrugated rib -   70 b Corrugated rib 

1. A heat exchanger for motor vehicles, in particular a cooler for cooling coolant for a heating or air conditioning system of a motor vehicle, having an inlet opening and an outlet opening for a first medium such as a coolant, a plurality of header tubes which form two header tube devices which are spaced apart, and having a plurality of connecting tubes which are arranged between these header tube devices and, in order to form a fluidic connection between the two header tube devices open with, in each case, one of their ends into the one header tube device and with their other end into the other header tube device; these connecting tubes being arranged in such a way that they form at least two rows of tubes through which the first medium can flow in parallel and which are respectively formed by a plurality of connecting tubes which follow one another in the longitudinal direction of the header tube devices and between which intermediate spaces are respectively formed for a through-flow of air, at least one of the header tube devices acting as a deflecting device in such a way that the flow direction of the first medium is deflected at least once between the two header tube devices in each of the rows of tubes, wherein the number of changes in the flow directions between the header tube devices in the rows of tubes is identical.
 2. The heat exchanger as claimed in claim 1, having an inlet opening and an outlet opening for a first medium such as a coolant, a plurality of header tubes which form two header tube devices which are spaced apart, and having a plurality of connecting tubes which are arranged between these header tube devices and, in order to form a fluidic connection between the two header tube devices open with, in each case, one of their ends into the one header tube device and with their other end into the other header tube device; these connecting tubes being arranged in such a way that they form at least two rows of tubes through which the first medium can flow in parallel and which are respectively formed by a plurality of connecting tubes which follow one another in the longitudinal direction of the header tube devices and between which intermediate spaces are respectively formed for a through-flow of air, at least one of the header tube devices acting as a deflecting device in such a way that the flow direction of the first medium is deflected at least once between the two header tube devices in each of the rows of tubes, wherein when the first medium enters the first header tube device it is divided into two partial flows to the connecting tubes, in particular flat tubes, of the first row of tubes and of the second row of tubes.
 3. The heat exchanger as claimed in claim 1, wherein each of the header tube devices has different header tubes for different rows of connecting tubes.
 4. The heat exchanger as claimed in claim 1, wherein a first component heat exchanger and a second component heat exchanger which each have: an inlet opening and outlet opening; two header tubes which are spaced apart; and a plurality of connecting tubes which follow one another in the longitudinal direction of the header tubes and which, in order to form flow connections between the header tubes open, in each case with one of their ends into the one header tube and with the other end into the other header tube, connecting tubes which follow one another in the longitudinal direction of the header tube being spaced apart from one another forming a respective intermediate space for an airflow which flows transversely with respect to the connecting tubes, and at least one of the two header tubes acting as a deflector device so that various groups of connecting tubes through which there can be respective parallel flows are connected in series so that a first medium, such as a coolant, can flow through them in succession in opposite directions, the flow routing of this first component heat exchanger and of this second component heat exchanger for the first medium, such as a coolant, being of essentially identical embodiment between the respective inlet opening and the respective outlet opening, and on the one hand the inlet openings of these component heat exchangers being connected, and on the other hand the outlet openings of these component heat exchangers being connected, and specifically in such a way that the first medium can flow in parallel through these component heat exchangers.
 5. The heat exchanger as claimed in claim 4, wherein the component heat exchangers are of essentially identical embodiment.
 6. The heat exchanger as claimed in claim 1, wherein the connecting tubes are each embodied as flat tubes, with preferably the two respective end regions of the flat tubes being rotated, specifically particularly preferably through 90° in each case, in relation to a respective region lying between these two end regions.
 7. The heat exchanger as claimed in claim 6, wherein the flat tubes each open with their rotated end regions into a header tube, the relatively long sides of the cross section which are formed in the cross section of the connecting tubes considered perpendicularly with respect to the longitudinal axis of the connecting tube enclosing, in the junction regions, an angle with the longitudinal axes of the header tubes or header tube devices which is smaller than 80°, these relatively long sides preferably being oriented parallel to the longitudinal axes in the junction regions.
 8. The heat exchanger as claimed in claim 1, wherein the component heat exchangers and/or rows of tubes are arranged adjacently.
 9. The heat exchanger for motor vehicles as claimed in claim 1, wherein ribs are respectively arranged in the intermediate spaces for a through-flow of air.
 10. The heat exchanger as claimed in claim 1, wherein the header tube devices are respectively formed by a plurality of header tubes with the circular or virtually circular internal cross section.
 11. The heat exchanger as claimed in claim 1, wherein dividing walls are provided in the header tubes by at least one of the header tube devices, specifically in particular dividing walls which divide regions of the interior of the respective header tube in the longitudinal direction of the header tubes.
 12. The heat exchanger as claimed in claim 1, wherein a thermal separation is provided between adjacent connecting tubes through which there can be a flow in opposite directions, said thermal separation being formed in particular by an enlarged distance between these connecting tubes compared to the distance between other adjacent connecting tubes of the same row of connecting tubes or of the same component heat exchanger.
 13. A device for heating and/or air conditioning the passenger cell of a motor vehicle, wherein the device has a heat exchanger as claimed in claim
 1. 14. A motor vehicle having a passenger cell and a device for heating and/or air conditioning this passenger cell wherein the device for heating and/or air conditioning this passenger cell has a heat exchanger as claimed in claim
 1. 